The Editor Grovels

Dik Leatherdale

The first issue of Resurrection for which I have been responsible, dropped onto
the doormats of CCS members early in August. Or, at least, it dropped onto the
doormats of most members in August. Sadly, something appears to have gone wrong
with the distribution, with some members receiving two copies and others
receiving none at all! It is doubly embarrassing to report that our gallant
chairman’s mat remained unblemished by copies of Resurrection, as indeed,
did my own.

So my first task is to apologise to all those members whose copies went astray
and to ask anybody who has yet to receive Resurrection 43 to get in touch with
Kevin Murrell, our long suffering secretary - email, letter, carrier pigeon -
your choice. Contact details are on page 31.

In Resurrection 44, we profile Donald Davies, the man who brought packet
switching to the world and so opened up the possibility of the Internet. It is
difficult to exaggerate the importance of innovation on this scale, yet the work
was done, not in some vast telecommunications corporation, but at the National
Physical Laboratory in Teddington, a mere stone’s throw from
Resurrection’s busy editorial office.

Our feature article, in this edition, is our chairman’s erudite account of
the development of Titan, also known as the Ferranti Atlas 2. Here is Titan on
a moderately busy day -

News Round-Up

The financial plight of Bletchley Park has attracted the attention of the
heavyweight press. In July The Times published a letter from some 97
distinguished academics, pointing out the significance of Bletchley Park. Not to
be outdone The Independent initiated a campaign of its own the following month,
publishing no less that five articles in one day, including an editorial, in
support of Bletchley Park. Both papers have published follow up letters and
articles.

As a result of all this publicity, visitor numbers have shot up, with an
increase of 30% from 2007 and an extraordinary attendance of over 3,000 during
the August Public Holiday.

Meanwhile, the e-petition mentioned in Resurrection 43(petitions.pm.gov.uk/BletchleyPark) has risen to fifth place in the Downing
Street list of 5,000 e-petitions, with no fewer than 15,533 signatures as
Resurrection went to press. This is important because the top five petitions are
displayed on the system front page, thus, with luck, attracting yet more
signatures.

Finally, welcome light relief in the form of a BBC Radio 4 comedy series,
‘Hut 33’, which was recently repeated. Starring Robert Bathurst, it
featured the unlikely adventures of a group of wartime codebreakers
characterised as upper class twits. Well, it made me laugh! No doubt, it will be
repeated again on BBC 7 in due course.

101010101

Donations to the National Museum of Computing have risen sharply recently with
several substantial private donations and a magnificent $100,000 donation from
cryptography company PGP and from IBM who, in September, led a kick-start
initiative to encourage further donations from the technical community across
the globe. See www.pgp.com/stationx.

An Elliot 905 has been acquired, and has been installed at Bletchley Park, near
the Elliot 803B.

101010101

We regret to report the passing, in August, of Sir Edwin Nixon, Chief Executive
and then Chairman of IBM UK from 1965 to 1990.

101010101

The Science Museum in London has put the first version of ERNIE, the machine
built in the 1950s to select winning Premium Bond numbers, on display in the
museum in Kensington
(www.sciencemuseum.org.uk/visitmuseum/galleries/ernie.aspx).
Retired in 1972,
ERNIE 1 has since been in store at Wroughton. Like Colossus, ERNIE 1 was
designed by the late Tommy Flowers and built at Dollis Hill.

101010101

News from our American cousins. The IT History Society
(http://ithistory.org)
has recently achieved a membership of more than 400. The IT History Society,
formerly known as the Charles Babbage Foundation, was created with the goal of
“enhancing and expanding works concerning the history of Information
Technology, and demonstrating the value of IT history to the understanding and
improvement of our world”.

101010101

The Heinz Nixdorf MuseumsForum
(http://en.hnf.de/default.asp)
claims to be the
largest computer museum in the world. Located in the former administration
centre of Nixdorf Computer AG, in Paderborn, northern Germany, it boasts some
5,000 objects and an exhibition area of 18,000 square metres.

Society Activity

Pegasus Working PartyLen Hewitt and Peter Holland

Pegasus continues to run well after its long rest. We have had minor problems
with the alternator and power run up, but in general, Pegasus is working well.
Following the completion of the special Babbage Engine, the temporary screens
have been removed (after five years) and ERNIE 1 is now on display (see above).
This has opened up the area and generated a lot more interest on “In
Steam” days, which is always welcome.

We have still not been able to find a Creed engineer who could handle our Type
54 teleprinters. If there are any out there please get in touch.

Our “In Steam” days are every other Wednesday from 5th November,
switched on from 11:00 to 15:00.

Contact Len Hewitt at .

Bombe Rebuild ProjectJohn Harper

In previous reports, I have mentioned our Checking Machine. Although this is a
fairly simple device, we increasingly realise how important this was in
successfully finding original Enigma settings. As many will have read
previously, we rebuilt one of these machines to go alongside our Bombe.
Electrically, it is very similar to a German Enigma machine in that, when one
presses a key, a different light is illuminated, the current having passed
through three drums, a fixed reflector and back through the drums. There is no
need for a stecker board (see Resurrection issue 6) in the way that it is used
because it works on the drum core settings. It does not, however, have any drum
progression mechanism. This is done by hand (and has to be) for the intended
process.

The machine is used to check whether the results a Bombe produces when it stops
truly represent those expected from the menu. For example, one of our test jobs
comes up with four stops, only one of which is correct. The incorrect ones are
due to the fact that the menu is not fully comprehensive. There is a trade-off
between making a menu larger (and so losing overall machine capacity) and
encountering a number of incorrect stops. As the Bombe can be restarted whilst a
stop is being checked on the Checking Machine, little overall time is lost.

The way in which the machine is used is that all the positions on the menu are
checked, one at a time. At each step, the letter illuminated is noted and after
the drums have been moved to the next position on the menu this letter is input,
the result noted and so on, until a complete loop has been made around the menu.
If the last letter lit is the same as that input at the beginning of the
operation, then this is likely to be a good stop. If it isn’t, then this
stop is of no use and another has to be found.

We now have a three wheel German Enigma machine on display in our area which
(almost) completes our full set of hardware used to break Enigma ciphers at
Bletchley Park during WWII.

I say “almost”, because, as reported previously, we have now
identified the special Typex used in the Bletchley Park machine room. This was
used by the lady and others of whom I spoke in my Spring 2008 report. It used a
method called ‘clonking’ to find the rest of the settings used by
the German operator after a good stop had been verified on the Checking Machine.
This machine appears to be based on Typex subassemblies, but not in any form
previously identified. The base casting is lower, as if the bottom two inches
have been removed, and no cover is fitted at the front. The keyboard is
virtually the same as a standard Typex, except that the mechanism that inhibits
more than one key being depressed has been removed. The ‘scrambler’
unit appears to be completely standard. We would like to reproduce this machine.
So if any reader knows of a source of Typex sub-assemblies, we would be very
pleased to hear from you.

Recently Their Royal Highnesses the Prince of Wales and the Duchess of Cornwall
visited Bletchley Park. We were one of the selected stopping points and they
spent about 10 minutes with us. By prior arrangement, Prince Charles started our
machine and appeared to be very pleased with what he saw working. In fact, he
looked much more closely at our efforts than he had planned. All in all, the
visit to our Rebuild and to the whole of Bletchley Park was considered a great
success.

Sponsor Sought for Bombe Rebuild Enhancement

The Bombe Rebuild has now been complete for over a year. During this time,
numerous WWII jobs have been re-run successfully. However, we have not been able
to attempt some of the decrypts in the Bletchley Park Archive. These require the
full set of eight drums rather than the normal five that mirrored the wheels
used in German army and air force three wheel Enigmas. We would very much like
to enhance our Bombe with the three extra drum types. We have a substantial
proportion of the necessary components left over from the original production,
but there are a few unique parts still needed. We estimate that we can make
these for £2000. We are therefore seeking a sponsor who could be
identified with this valuable enhancement.

Dave is starting to undertake a review of the collection of machine emulators
and other software which the Society holds at
sw.ccs.bcs.org. He hopes to report
on its origins and will, in particular, examine some of the older material that
we hold.

Our Computer Heritage Pilot ProjectSimon Lavington

Some progress has been made with listing all the English Electric DEUCE and KDF9
computers to have been built. Since no manufacturer′s definitive delivery
documents have come to light, compiling this information relies on the discovery
of subsidiary source documents and upon the memories of those who worked on
these machines. If any Resurrection reader is familiar with either of these
English Electric computers, please take a look at:
www.ourcomputerheritage.org/wp and follow the links to: ′N1X1: List of
English Electric DEUCE deliveries′ and ′N4X1: List of English
Electric KDF9 deliveries′ to see whether our story accords with your
memories. If you have any comments or, better still, original documents that
could improve upon the accuracy of these two lists, then please let me know at
.

There are areas of the Pilot Study where we still need help. Particular
computers that lack active volunteers willing to compile technical information
include: the Ferranti Mark 1 and Mark 1 Star; the English Electric DEUCE, KDN2,
KDF7, KDF6 and KDP10 computers; the BTM HEC and 1200 computers. If any reader is
familiar with one of these machines and is able to devote time to compiling
technical information for eventual uploading to the Our Computer Heritage
website, then we′d be keen to hear from you.

North West Group contact details

Pioneer Profiles - Donald Davies

Martin Campbell-Kelly

Donald Davies was one of the most outstanding British computer pioneers to have
led the field in the post-war decades. Davies, who spent most of his career at
the National Physical Laboratory (NPL), was a multi-talented engineer,
administrator, and policy-maker. All of his talents combined when he invented
packet switching in the 1960s, today a foundation technology of the Internet.

Donald Watts Davies was born, in modest circumstances, in Treorchy in the
Rhondda Valley. Following the death of his father, the family moved to his
mother′s birth town of Portsmouth. Davies entered Imperial College at the
age of 19, graduating with a first class honours degree in physics in 1943. He
spent the remainder of the war years on the atomic weapons ″tube
alloys″ project at Birmingham University, as an assistant to Klaus Fuchs.
At the end of the war, Davies returned to his scientific studies at Imperial
College, obtaining a first class honours degree in mathematics in 1947. He also
won the Lubbock Memorial Prize as the outstanding mathematician of his year.

In 1947, Davies obtained a position at the NPL, where Alan Turing was designing
the ACE computer. The ACE project was over-ambitious and it foundered for two
years due to bureaucratic obstacles, eventually prompting Turing’s
departure. Davies emerged as probably the only person at the NPL with the right
blend of electronic, mathematical, and administrative capabilities to get the
machine built. Instead of Turing′s ambitious ACE project, he settled for
the Pilot ACE, a small experimental model. The machine first worked in May 1950.
It proved sufficiently powerful that a commercial spin-off, the DEUCE, was
manufactured by English Electric and became one of the best selling British
computers of the 1950s.
Although Davies had taken on these heavy
responsibilities (he was not yet 30), he still found time to show his inventive
and playful side. For example, he built a noughts-and-crosses playing machine
which was demonstrated at a Royal Society soirée in 1949.

Demonstrating his noughts and crosses
machine at the Royal Society in May 1949

After the construction of the Pilot ACE, Davies became involved in computer
applications such as a road traffic simulation and machine translation. In 1963,
he became technical manager of the Advanced Computer Techniques Project, a
government initiative to keep the British computer industry at the forefront of
research. In 1965, he was seconded to the new Ministry of Technology in Harold
Wilson’s Labour Government which, famously, had been elected on the lure
of its “white heat of technology” manifesto.

In 1966, Davies returned to the NPL to become Superintendent of its computing
activity, which had lost its way during the previous decade. Renamed the
Division of Computer Science, Davies reinvigorated computer research and gave it
a more practical focus. It was in this context that the work on data
communications and packet switching was done. Davies had become interested in
data communications following a visit to the Massachusetts Institute of
Technology in 1965, where he had seen one of the first time-sharing computer
systems in which a single mainframe computer was shared among many interactive
users. Davies recognized that a major problem with the remote use of time-
sharing systems was the “bursty” nature of the data communications
traffic. A user sitting at a terminal occupied an entire telephone line, but
spent most of the time thinking, so that the phone line was only about two
percent utilised. This made access to time-sharing computers via long-distance
telephone lines prohibitively expensive. His concept was to apply the principle
of time-sharing to the data communications line as well as the computer. The
result was a technique he called packet switching, by which a single line was
shared between many users who sent their data in individual packets. A small,
experimental network was established at the NPL in 1970, and a great deal of
theoretical work on network simulation and congestion was undertaken in the
1970s.

Davies had an ambitious plan for a network of packet-switching centres that
would create a national infrastructure for computer communications. However, it
was a decade before the lethargic, pre-privatisation Post Office
telecommunications division created even an experimental packet-switching
service. In the United States, things moved much faster. In the Department of
Defense′s Advanced Research Projects Agency (ARPA), Larry Roberts was
struggling with the same problem as Davies. As soon as he heard of packet
switching, he built it into his experimental computer network. This network, the
Arpanet, was the prototype for the Internet.

In 1979 Davies stepped down as Superintendent, to return to research on his
favourite topic of data communications. By now, computer communications had
become an everyday reality. In financial institutions, in particular, a whole
new set of problems of data security and encryption had surfaced in which Davies
immersed himself. He wrote a major book on computer network security. After his
retirement in 1984, at the age of 60, he became a leading consultant on data
security to banks. In 1987, he became a visiting professor at Royal Holloway and
Bedford New College.

Davies received numerous awards and honours, largely for his work in data
communications. He was one of the first distinguished Fellows of the British
Computer Society in 1975. He was awarded a CBE in 1983, the von Neumann medal in
1986, and was elected a Fellow of the Royal Society the following year.

Davies always had a deep interest in computer history, and the leisure of
retirement combined with his professional expertise in data security enabled him
to become a recognised authority on wartime cryptographic machinery.

Donald Davies passed away in 2000.

CCS Web Site Information

The Society has its own Web site, which is located at
www.computerconservationsociety.org.
It contains news items and details of forthcoming events and also
electronic copies of all past issues of Resurrection, in both HTML and PDF
formats, which can be downloaded for printing. We also have an FTP site at
ftp.cs.man.ac.uk/pub/CCS-Archive,
where there is other material for downloading
including simulators for historic machines. Please note that this latter URL is
case-sensitive.

Titan - the Poor Man’s Atlas?

David Hartley

Our esteemed chairman tells the story of the Cambridge development of the
Ferranti Atlas - Titan.

Perhaps I should first explain Titan’s relation to Atlas. Titan was the
name of the prototype Atlas 2, being a cut-down version of Atlas, properly known
as Atlas 1. But I must also, briefly, tell the history of computing in Cambridge
which led to the development of Titan.

EDSAC

EDSAC was the first Cambridge machine. It was the world’s first stored-
program computer to go into regular service after the Manchester SSEM (which
didn’t go into service). Of course, Manchester was one year ahead of us -
we admit that. EDSAC was built between 1946 and 1949 and immediately went into a
regular user service. Maurice Wilkes’ policy for the machine was that, as
soon as it started working, users across the University should be encouraged to
use it for their research. Maurice Wilkes sent round a note to key professors,
saying: “I have built an automatic calculating machine; please come and
use it”. And he even let research students use it - which, in many
institutions, was unheard of in case the precious machine was wasted.

The basic statistics of EDSAC were as follows: it had a speed of 300
instructions per second; it had two kilobytes of memory in mercury delay lines;
there was no online file storage, apart from an experimental magnetic tape
system; and, at its peak, it had about 50 users. In effect, EDSAC replaced
mechanical hand calculating machines. So it was 1,500 times more powerful than
the technology it displaced. By this measure, it was the largest step forward in
computation power in each of the technology generations. EDSAC was taken out of
service in 1958.

EDSAC 2

EDSAC 2 was the second Cambridge machine. It was started in 1952, and was in
service from 1958. The machine had packaged circuitry with replaceable plug-in
units, the largest of which was several feet long. It was made up of miniature
vacuum tubes. In the mid 1950s, the ferrite core became a feasible option and
this technology was adopted. The machine also had a reasonably reliable file
store made from two twin magnetic-tape drives purchased from Decca.

EDSAC 2’s job queue was its users, who were able to test their programs in
two or three periods each day. They queued up by the input desk. Each user was
allowed three minutes to read in their programs and data, run a brief test and
collect output from a paper-tape punch or printer. The job control scheduler was
a line of other users who provided the necessary peer pressure to keep to time.

EDSAC 2 was the world’s first microprogrammed computer and had built-in
floating-point arithmetic. The instruction rate was 10,000/sec (only 40 times
that of the EDSAC), with 88Kbytes of random-access memory. The peak user
population was around 200 users.

The close down of EDSAC 2 in 1965 started a peculiar Cambridge tradition. We
would never ‘open’ new machines, because everyone knew that new
machines were usually suspect, tended not to work very well and what software
they had was often unreliable and late. In short, users feared and mistrusted
new machines. But, by the time one was closed down, users had developed an
affection for the machine, and closure was a cause of emotion. Users crowded
into the computer room, and watched Maurice Wilkes feed in the final job (on
black punched tape, of course). EDSAC 2 duly played the Last Post. Grown men
were seen to weep.

Titan

In 1960, half-way through the life of EDSAC 2, Cambridge started thinking about
its third machine. Although we had enjoyed building new machines from scratch,
we were conscious that our users wanted something more ready-made, so we sought
to buy one.

And, of course, it had to be something that was worth buying, a machine
significantly more powerful than EDSAC 2. At about that time, the government
authority for funding universities was making grants to enable them to acquire
their first computers. A grant of £250,000 was indicated for Cambridge. At
that time many universities were buying the English Electric KDF9 which cost
about £250,000. KDF9 was a fine machine, but EDSAC 2 was already the power
of a KDF9, and there would be no point in us having one. After some searching,
Cambridge found two machines that were sufficiently more powerful than EDSAC 2
to be worth considering and could take a growing user load.

One was the Ferranti Atlas and the other the IBM 7090. We could afford neither.
There had been intensive talks with Ferranti and IBM, but a funding solution
eluded us. Then suddenly, out of the blue, Maurice received a letter from Peter
Hall who was then Ferranti’s computer manager in Manchester. Here are some
quotations from that letter:

“Your computer problem is occupying our minds very much at the
moment.........Cambridge and Manchester Universities are unique in that they are
both machine designers and builders. Can we not exploit this at Cambridge? If
we, Ferranti, sold you at “works cost” (he never defined
“works cost”) un-commissioned standard parts of the present Atlas
and a slow store, could you do the necessary connecting together, design any
special bits, modifications as necessary and commissioning? In other words, we
will sell you large chunks of standard hardware and you do the rest.

“In return for letting you have this hardware at works cost, you would let
us have all designs and information on the work you do relating to it; e.g. in
connecting in a slow store, programming etc. At a very rough preliminary guess
we would, under this arrangement, let you have the following bits of hardware
... “

Peter then listed the parts to be provided, at ‘works cost’,
including the CPU, minimal control for peripherals and magnetic tape units, slow
(6μsec) memory, power supply, card reader, printer and control desks.

“I must emphasise that these items will be un-commissioned, and you would
not just fit them together. We would, of course, send you all information to
commission them yourself. You might like to send someone up here during
commissioning of earlier machines, and we could probably send a man to work with
you in Cambridge.

“This is just a thought. It’s very sketchy, but what do you think ?
It seems to me that, if you have the necessary effort, it will help both you and
us, because this would then be the basis for a second model of Atlas for the
Ferranti market.”

Cambridge hadn’t many options available but, with the experience from the
two EDSACs behind us, we were game for the challenge. We were being offered half
a machine at a price we could afford and had the opportunity to work with
Ferranti to design and prototype the rest of it.

There was discussion on what to call the new machine. In Cambridge there were
some who preferred EDSAC 3, while Ferranti had a tradition of using names from
mythology. “Titan” was suggested and started to be used. Then there
was another letter from Peter Hall:

“We’ve been thinking about the name for this machine, and we think
we want to call it Atlas 2”

Maurice Wilkes diplomatically accepted the suggestion, although Titan remained
the name for the prototype Atlas 2.

Atlas 1 had a very elaborate one-level store - with page-address registers,
drums and sophisticated software to transfer information between one and the
other seamlessly: a very large virtual memory. So, system programs and user
programs could spread themselves widely in the memory address space but at a
substantial cost in hardware and in software complexity. Titan simply could not
afford this.

But nevertheless, the requirement was to design an efficient multiprogramming
system, so we had to make do with the poor man’s paging system: two
registers, one determining where the current program started, and one saying how
long it was.

The hardware peripheral controller had to be re-designed because, again, Atlas 1
was complex with many kinds of peripheral device, whereas all we needed was to
control paper-tape readers, paper-tape punches, printers and magnetic tapes.

Magnetic tapes were the same as on Atlas 1: one inch wide tape containing
pre-addressed 512 word blocks of data. Tape control on Titan was innovative: when
reading a block, the controller could scatter the data in eight 64 word
blocklets to eight separate memory addresses; similarly the hardware could
collect eight separate blocklets from memory and store them in a single block on
tape. This meant that memory management for data streaming and even user memory
allocation could be handled in quite small units, important when you only have
16k words to play with.

David Wheeler was the design authority for Titan/Atlas 2. He had full control
over the hardware team, consisting of both Cambridge and Ferranti staff; such
was the trust between Ferranti and us. At the same time, Roger Needham, who was
then just finishing his research thesis, helped David by writing design
automation software on EDSAC 2, which laid out the printed circuit boards. Two
Ferranti engineers were seconded to us for installation and commissioning. They
seemed to camp out in the Eagle - years earlier, the pub of Crick and Watson
fame.

A User's View of Titan

To house the machine, the University let us have an old-fashioned, tiered
lecture theatre. The room had to be gutted and the floor levelled, but we kept
the very top tier as a viewing gallery; important because we already realised
that a machine of this type could not be operated by the users themselves, and
that they were unlikely to love a machine they couldn’t see.

I’m told there is a published history of Ferranti which claims that Titan
was built because Cambridge wouldn’t agree to have any machine that
originated from Manchester. Not true! Titan was a machine fundamentally designed
by Manchester. We were very happy to have it.

System Software

The Titan operating system was necessarily different from the Atlas 1 supervisor
which was built around the hardware one-level store that we didn’t have.
The Atlas 1 system programmers could just scatter programs and data all over
memory and let the one-level store do the memory management; whereas on Titan,
to keep the machine busy, we had to be very careful how we buffered data. One
must remember that, in those days, operating systems were written not to make it
easier for the user to use, but to optimise the efficiency of the machine - to
make sure that the CPU was kept busy and not kept waiting for input and output.
In fact operating systems in those days tended to make computers less not more
easy to use, and there are probably few who remember the dark ages of the
Fortran Monitor System. Nowadays ... - but one sometimes wonders!

There was no option for the Titan operating system to be other than a total re-
design, although we had the benefit of the process technology devised at
Manchester. This gave rise to what was essentially a separate joint project with
Ferranti; a team at Cambridge working with a Ferranti team located at Lily Hill
in Bracknell. The Cambridge team consisted initially of David Barron, Barry
Landy and I. The Ferranti team was led by Chris Spooner.

It was Chris who brilliantly designed the input-output buffering system, the so-
called Magnetic Tape Well. Like the Atlas 1 system, the Titan supervisor was
designed as a multi-programming operating system, with the well acting in place
of the one-level store and drum.

The basic hardware was delivered to Cambridge in 1963, and enough of it was
commissioned to enable us to run programs in October that year. The supervisor
and other system software was scheduled to become operational by late 1964. Like
everyone else before and since, we were no exception to the rule that big
software projects are always late.

It was at about that time we heard that Manchester was also running late. But
Manchester had been rather astute: a temporary operating system and a temporary
Mercury Autocode compiler had been quickly developed which were giving some user
service admittedly in a non-optimal manner. David Barron, Chris Spooner and I
travelled north to see for ourselves and were duly impressed. Any service is
better than none, and theirs was holding off what would otherwise have been
extreme user pressure.

We came back fired with enthusiasm and realised that this would provide an all-
important breathing space. Two persons were commissioned to build a temporary
supervisor and a temporary compiler. The temporary supervisor was written by
Peter Swinnerton-Dyer; it had single serial job processing, no multi-tasking,
and all input-output buffering was held in memory. This was inefficient, but it
worked. At the same time, Maurice Wilkes himself wrote an EDSAC 2 Autocode
compiler using his innovative list-processing system known as WISP. Later, Peter
Swinnerton-Dyer re-wrote the compiler using more conventional techniques.

As the so-called main supervisor project dragged on, Peter said he thought he
could write something better than the temporary supervisor, and started
designing an input-output buffering system using magnetic tape. This worried
those of us on the main supervisor team, realising that if we didn’t get a
move on, we would have system software written entirely by one person. An
admirable incentive!

The temporary supervisor was operational from 1964 and the main supervisor was
re-scheduled for late 1965. It didn’t, in fact, see service for a good
year after that, but that is another part of the story.

Time Sharing

As explained earlier, the main supervisor was a joint project with Ferranti.
Like Atlas 1, it was a multi-programming job system: no terminals, no
interaction, straightforward job input through paper tape readers or card
readers into a magnetic tape buffer, spooled off, scheduled and run. Because the
system was multi-programming, short jobs could overtake long jobs. Quick jobs
could be scheduled with high priority. But everything was run strictly offline.
Whereas the EDSAC 1 and 2 were machines that the users actually ran themselves,
it was considered impractical to let users anywhere near Titan. Instead, they
would hang their paper tapes on a peg on the wall, and their results were hung
on the same peg somewhat later; apart from the opportunity to schedule the
relative priority of jobs, this was little better than the batch operating
systems of those days.

While the main supervisor was still under development in 1965, Maurice Wilkes
set off for one of his regular visits to MIT in the US, where he saw the CTSS -
the Compatible Time-Sharing System - on an IBM 7090. Maurice was totally
enthused by what he saw and returned saying time sharing was the future, and
this is what we must do. Given that we were several years into a very different
kind of operating system, the news was hard to take.

After a good deal of encouragement from Maurice, and some hard thinking, we
agreed that if MIT could do it, so could we. What was more, we could and would
do it better! There were, of course, a few problems to overcome in re-directing
the project. Firstly, ICT (who, by this time, had taken over Ferranti’s
large computer interests) was working on a version of the supervisor that was to
go to the Atomic Weapons Research Establishment at Aldermaston. The requirements
were already diverging. So we virtually had two separate teams developing two
different systems. It was mutually agreed Cambridge and ICT would go their
separate ways.

Then, we made some hardware changes to Titan. David Wheeler designed a second
pair of base and limit registers to provide what could be described a crude and
simple form of memory segmentation. Thus a program could be securely located in
two parts: the program itself and its data. If the program was interactive, we
could get away with a single copy in memory with multiple copies of the data,
one copy for each interacting user. For example a text editor, so important in a
time sharing system, might be contained in a 512 word block, with the data for
each user located in separate 64 word blocklets. This was essential because
there was no way we could implement the so-called memory swapping of other early
time-sharing systems - there was no fast data channel to a drum store.

But there had to be some form of sizable backing store with efficient random
access. So, with the invaluable assistance of Basil de Ferranti we acquired a
disc; this was donated by ICT in return for access by them to the completed
system - something they never claimed. So, a Data Products disc store was
procured which initially provided a user file store.

The third hardware development was to build a multiplexor to link local and
remote teletype terminals into the main machine. Designed by David Wheeler, it
had a few odd features. Characters read from a terminal were presented to the
machine in reverse order and inverted; we quickly learned the technique of look-
up tables, which was easier than persuading David to re-engineer his design.

But there was still one problem we had to solve, caused by the inability to
implement efficient program swapping. Our new disc was adequate for user files,
but not fast enough to swap active programs and their data in and out of memory.
We had to turn our multi-programming system into a multi-access system. This was
achieved by nothing more than sleight of hand.

Utility programs, such as text editors or file management functions, were
written in tight code with minimal in-memory data, so that many users could be
served by them using very little memory - just one copy of the program with as
many blocklets of data as active users. A user program, however, could not
access the terminal and could only read and write data to the file store. But as
soon as the program was waiting for user input, any collected output was
immediately spooled to the terminal. So a user program could undertake tasks on-
line with immediate input-output, but could not actually do single character
interaction. We therefore provided what might be termed interactive job-step
running, which was a substantial advance on the old off-line regime and was what
most people needed. We managed to support about 24 simultaneous users on what
was, by now, a 48k word machine. The sleight of hand was very successful.

A file store for user programs and data was largely the work of Sandy Fraser.
Sandy designed a sophisticated file system with very flexible user access
controls. He developed mechanisms to enable the owner of a file to control who
could write, who could read or who could only execute a file. Then it could
control not only which user could do what, but which program could do what.
There was a sophisticated backup and restore regime where files were
automatically copied to magnetic tape and recalled on failure.

There was an advanced system for controlling the use of the very limited file
space available. As well as an assigned upper limit, each user was allocated a
quota which was added to his account daily and from which his actual use was
subtracted each day. Users could create and modify files only while their
accounts remained positive, thus giving flexibility and an incentive to save.

Finally, which we didn’t rate as particularly important at the time, there
was the security of passwords. In those days, one tended to store passwords in a
system file which you did your best to hide from enthusiastic inquisitive users.
But, if someone cracked security and gained access to that file, everything was
immediately compromised. Roger Needham hit on the idea of scrambling passwords
with a one-way encryption algorithm. The system only needed to compare one
scrambled password with a newly introduced scrambled password to check security,
and the scrambled passwords were of no use to a hacker. The technique is now
applied in most password handling systems.

Thus, it turned out that a system implemented in a well-designed software
methodology could be adapted from an off-line multiprogramming facility into a
time-sharing on-line system, providing a general-purpose university computing
service.

Applications

Titan provided the University’s computing service for a good many years,
and it was used for applications in research and teaching; it was used by
scientists, by non-scientists and it was used by students. New areas of
application were pioneered on Titan. The one to which I wish to refer here is
Computer Aided Design.

A CAD research team was established in the laboratory. A PDP7 with a high-
performance display was connected to Titan. These facilities enabled the CAD
team to take CAD from a research topic in computing to become an application
tool in engineering research. Later, when a second Atlas 2 was installed in a
government-created institute in Cambridge, CAD techniques were systematically
introduced into industry.

The basic statistics of the final Titan installation were an instruction rate of
0.25 MIPS, 0.75 Mbytes of memory and 128 Mbytes of file storage, and getting
near to 1,000 users. Most of those users worked on-line, at least for their
program development, controlled by some sophisticated resource allocation and
control techniques. It was still a far cry from today’s personal
computers, but by the standards of the day, it was a powerful machine serving a
lot of users.

Closure

Titan lived on until 1973 when it was closed down and replaced by an IBM
370/165. We continued the tradition of close-down ceremonies. By then, Titan was
in another building. We assembled the users in a nearby 500-seat lecture theatre
which was filled to capacity. Live CCTV pictures of Titan were transmitted into
the theatre, and a dramatic scene followed. Talks and tributes were first given.
Then the final Close Down command was shown being typed on the operators’
console, followed by the chief systems programmer shutting down the operating
system. The hardware technicians went round the computer room turning off all
the units, and tension grew in the lecture theatre. Many were not sure how to
get through the next few minutes. Finally, the Chief Engineer appeared, and
approached the main power switch; he put his big hand on the switch and the
camera zoomed in. The switch was turned and it went round and round and round (a
student had loosened the switch the night before). The tension in the lecture
theatre was suddenly broken, and everyone had a good laugh. That’s the way
to say good-bye to a faithful old computer!

Summing up

So, what did we actually achieve? Firstly, we got a big enough third computer
for our funds. We also helped Ferranti develop a new version of Atlas. The
operating system was pioneering in many ways and provided practical and
efficient time sharing facilities for a large user population. To support nearly
1,000 users on a single machine was crazy when you think about today’s
technology.

The late Roger Needham, at the 50th anniversary of the EDSAC, ended a
presentation about Titan in his inimitable fashion:

“It was fun. If you are in our trade, nothing gives you a charge like
having put together a system which nobody else can match.”

Chris Spooner read Mathematics at Trinity College, Cambridge in the early 1950s
and is reported to have achieved the top first in his final year. Sadly, he died
while this article was in preparation. This article is dedicated to him.

Editor’s note: This is an edited transcript of a talk given by the author
at the Science Museum on 20 September 2007. Contact David Hartley at
.

The Ferranti Sirius at Monash University

Barbara Ainsworth

Barbara Ainsworth tells the story of the Ferranti Sirius (or rather, several
Sirii) at Monash University in Melbourne, Australia. Incredibly, two machines
survive. One is now a centrepiece in their Museum of Computing History.

The Monash Museum of Computing History (MMoCH) was established in 2001 to
preserve the early computing equipment distributed around the different campus
sites that now form Monash University, Melbourne, Australia. Amongst these early
pieces was a Ferranti Sirius computer which was stored under a stairwell. This
computer has now been transferred to the MMoCH and is on permanent exhibition as
part of the museum’s display at Caulfield campus. The provenance of this
computer is an on-going research project of the MMoCH.

Initial research was focused on the Ferranti Sirius still on campus, but
references and personal recollections from early computer users proved to be
very confusing. Further investigations revealed that there were actually four
different Sirius computers on campus at different times during the 1960s. In
1962, these four computers were located at different sites; two Sirius computers
at the Melbourne Computer Centre operated by Ferranti Ltd, one at Monash
University Clayton Campus and one at a commercial research operation run by ICI
Australia & New Zealand (ICIANZ), at Ascot Vale.

Monash University entered the computing area in the early 1960s but there were
already local developments in computing in Australia during the late 1940s and
1950s. These were overshadowed when the major foreign companies expanded their
computer sales operations into the Australian market in the 1950s, establishing
outlets in Sydney and Melbourne. By 1962, there were about 80 computers
installed or on order around Australia. About a third of the computer
installations were located in private commercial operations. Eight universities
had installations including Monash University. A small number of government
departments had their own computer. As an alternative, the computer companies
operated service bureaux. IBM dominated sales at this time.

The Ferranti Melbourne Computer Centre was established in 1960 with Barry de
Ferranti as Sales Manager. Richard Cross and Richard Levingston moved from
England to work at the Melbourne Ferranti office. Robin Goodchild was the bureau
programmer and started with Ferranti in 1962. The Ferranti Melbourne office
operated from “Stanhill”, Queens Road, Melbourne. This busy Computer
Centre housed a 1,000 word Sirius and later, a 7,000 word Sirius. Barry de
Ferranti recalled that these machines were in great demand.

“The team I assembled to establish the Melbourne Computer Centre in
Stanhill, in 1960, helped promote technical computing in Victoria. Before long,
Melbourne-based government departments, manufacturers, universities and
utilities were loading our little Sirius beyond expectation; even a motor
journal ran a survey, with extraordinary response, causing us to work shifts to
cope.”

Ferranti produced a range of computers in the early 1960s, each named after
mythical figures, including Perseus, Pegasus, Sirius, Orion, Mercury and Atlas.
At Ferranti in the late 1950s, Gordon Scarrott developed an unusual transistor
circuit, the Neuron, for the Orion 1 computer. To test the Neuron circuit, a
test bed computer called NEWT was constructed. NEWT took on a life of its own
and was re-engineered and sold as “Sirius”. It was announced to the
public in a press release on 19 May 1959. It offered Sirius as a transistorised,
desk-sized, electronic, digital computer. The release claimed that it would be
the smallest and most economically priced computer in the European market.

Sirius was manufactured at the Ferranti factory in West Gorton from 1960 to
1963. J.F. Wilson records that the company produced around 22 installations.
Research shows 15 being sold to real customers and about five used by Ferranti
as demonstration models and in bureau services. Only seven were exported.
Strangely, four of these seven were sent to Melbourne, Australia.

Sirius was not the most powerful of computers. Its serial architecture kept the
cost and size down, but meant it was not particularly fast. It had only 1,000
words of store which could be increased to a maximum of 10,000 words. Ferranti
Ltd sold the basic CPU with 1,000 word capacity. Memory could be expanded by
adding on additional memory cabinets with 3,000 words of store. Input and output
was entirely by punched paper tape. However, it had some very attractive
features. It was one of the earliest computers to use transistors rather than
valves (vacuum tubes). So it was relatively small (small enough to stand behind
an office desk), had low power requirements (it ran off a standard 230 volt 13
amp socket) and had no need for special air conditioning. A full system consumed
about 2kW. It had a decimal display and a facility to slow the processor for
demonstration and educational purposes. It was a good, general purpose and
relatively inexpensive machine for its time, ideally suited to educational
establishments.

Monash University decided to purchase a computer in 1961. It was a new
educational institution, the University receiving its charter in 1958 and
enrolling its first students in 1961. Today, Monash University is composed of a
number of campus sites distributed around Victoria. The first campus under this
university title was located at Clayton.

Monash wished to create a computer centre to provide administrative support as
well as academic research facilities, as part of its new Clayton campus.

The Computer Facilities Committee was established under Professor Westfold,
Chairman of Mathematics, to investigate the different models available and
compare their prices and capabilities. The Computer Facilities Committee had
trimmed their report to consideration of two different computer models by 29
September 1961. The two frontrunners were the IBM 1620 and the Ferranti Sirius.

In December 1961, Professor Westfold delivered the final recommendation to
purchase a Ferranti Sirius to the Vice-Chancellor, Professor Matheson. Professor
Matheson officially ordered the Ferranti Sirius on 20 December 1961.

This offer was put at a cost of A£33,137. The tender gave a delivery
period of nine months from the confirmation of order.

Something Borrowed

As part of the contract, Ferranti Ltd offered to provide the loan of their new
7,000 word Ferranti Sirius, which was already being built in Manchester, until
the delivery of the University’s own computer. The Ferranti Bureau would
effectively be located at the University, but the Monash Computer Centre staff
would have direct access to the Sirius. The University would provide space for
the temporary loan of the 7,000 word Sirius, with two sets of Ferranti/Creed
model 75 tape editing equipment. Ferranti would supply a fully trained
programmer during office hours. The University needed to employ a computer
operator (referred to as ‘she’ in the proposal) to be trained by the
Ferranti programmer. The University would be able to book two hours / day free
of charge and up to three hours extra if the machine was not booked.

This shared arrangement was apparently quite successful. Ferranti Ltd completed
the production of a new Sirius for Monash University and it was shipped to
Australia in late 1962. Brian Parker was sent from England to help with the
installation. It was operating, after acceptance tests, by November. The
Ferranti Bureau 7,000 word machine then was returned to the Melbourne bureau.
Cliff Bellamy transferred from Ferranti to Monash University in early 1963. He
subsequently spent more than 30 years supervising and developing computer
facilities at Monash.

Our Own Machine

The Monash Sirius about 1963

In its quarterly report for January to March 1963, the Computer Centre gave some
details on the operations of the Sirius. They were operating the 4,000 word
Sirius with two paper tape readers and one tape punch. There were two Creed
teleprinters. Students were using the computer for elementary data processing
and technical computations. The Computer Centre was also actively encouraging
staff to learn Autocode and machine code programming. The largest single user of
the computer, in terms of hours, was the Administration Department, with 91
hours in the first quarter. Other major users were the Physics Department,
Engineering Faculty, Chemistry Department and the Computer Centre. However the
Maths Department only used three hours. The Sirius was in high demand. Bellamy
reported, in May 1963, that he expected the machine to be running two eight hour
shifts daily to meet user demand. Alan Cowley worked on the machine in 1963 and
he converted it to a real-time, interrupt-driven machine for a specific project
in the Chemical Engineering Department.

The Computer Centre at Clayton campus was expanded with the purchase of a CDC
3200 in April 1964. By 1967 the Sirius was probably only used about two hours a
day on an irregular basis as most work was run on the CDC 3200.

ICI Australia & New Zealand is Generous

In 1967, the University was offered the donation of another 7,000 word Ferranti
Sirius from ICIANZ, who had also purchased a Ferranti Sirius in 1962. Their
Ferranti machine had been installed at ICIANZ Central Research Laboratory at
Ascot Vale in late February 1962, having been purchased for A£40,000.
Brian Parker commented that this machine had reliability problems. The
processor backplanes had been resoldered to remove possible dry joints.

The Sirius was ICIANZ’s first computer. The company newspaper ICIANZ
CIRCLE holds several articles noting the arrival of the new computer. There is
also a quite detailed article on how the Sirius actually processed information,
including a strip of coded tape reproduced down the side of the page of the
article. Recently run on a simulator in the UK, this tape is indeed the code
relevant to the hypothetical problem described in the text!

The company continued to update their computing facilities. When they purchased
an IBM System 360 in 1966, it was decided that this was adequate for all their
computing needs. In 1967 ICIANZ offered to give their Sirius to Monash
University. The University accepted the donation of the ICIANZ Ferranti Sirius
but, in the Annual Report for 1967, the Sirius machines were described as
“Other Equipment”.

The original 4,000 word machine is described with the statement, “...is
maintained by, but has little other active support from, the Computer
Centre.” The ICIANZ machine is dismissed as well with the sentence,
“The original intention was to use it as spare parts but later it was
installed in the Chemistry Dept., for special duties.”

The Sirius installations were finally decommissioned in 1972. The original 4,000
word Sirius was relocated to open display in a building at the Clayton campus
until it was given to the Monash Museum of Computing History and placed on
display as part of its permanent exhibition at Caulfield campus in 2005. The
ICIANZ 7,000 word Sirius, located in the Chemistry Dept., was donated to Museum
Victoria in 1975.

Yet Another (Rather Special) Sirius

Meanwhile, a few miles away, the Chisholm Institute in Caulfield had developed
its own computing school during the 1960s. A second (1,000 word) Sirius computer
at the Ferranti Melbourne Computer Centre was relocated to Caulfield on lease.
It was then purchased in about 1964. The 1,000 word Sirius was originally built
as a prototype model. In 1961, it was exhibited, as a demonstration model, by
Ferranti, in the British Pavilion, at the Italian Centenary Exhibition in Turin.
It was then sent back to be used at the Newman Street bureau in London. Later it
was sent to the Melbourne Ferranti Bureau and subsequently transferred to
Caulfield Technical College. The College placed it in the Department of
Electronic Data Processing. On open days, staff would program the computer to
make “music”. The processor had an audio device which could be
programmed to make different tones. The computer could play several pieces.
Peter Juliff remembers the computer playing a theme from Bach’s 4th
Brandenburg Concerto and then “Cockles and Mussels”. The Sirius was
replaced by new equipment in the late 1960s and disappears from the record.

After several changes of name and various mergers, Chisholm Institute became
part of Monash University. The MMoCH is located at the Caulfield campus.

Looking Back

The decision to purchase a Ferranti Sirius in 1961 started a long development of
computer technology and education at Monash University. The Ferranti Sirius was
a small production computer, but it was an economical installation that suited
the needs of both academic and administrative operations in the early 1960s. The
large number of installations in Melbourne, nearly 20% of all Sirius computers
produced, reflects the sales abilities of the local Ferranti office. This small
computer had a significant influence on Monash University with all four
installations being associated with the University at some point during their
working life in Australia.

Sirius on Display at the Museum

Two of these installations have, fortunately, been preserved. The 4,000 word
Sirius is now on permanent display at the Monash Museum of Computing History, in
a dedicated showcase, supported by a range of input/output devices. The display
includes a short film “Instant Arithmetic”, produced in 1963 by S.E.
Fargher, which illustrates the process of calculating a problem on a Ferranti
Sirius for a non-academic audience. The larger 7,000 word computer, also
supported by a selection of input/output equipment, is in storage at Museum
Victoria. It is unfortunate that the 1,000 word Sirius, displayed originally at
Turin, has been lost. There is also no record of the fate of the 7,000 word
Sirius at the Ferranti Melbourne Computer Centre.

Cliff Bellamy, Director of the Computer Centre, noted in 1965 that “Monash
is probably the most computer-conscious university in Australia”. He
attributed this to the low average age of the staff and their acceptance of new
approaches to problem solving. He could have also cited the acquisition of the
Ferranti Sirius in 1962. The reputation and output from the Computer Centre
started on this early computer. Although the Sirius was small, it demonstrated
the potential of computing in the work of the University. The installation of
Sirius, in 1962, started the strong tradition of innovative computing at Monash
University.

The MMoCH has received invaluable assistance from Steve Poulton and the late
Brian Parker, with many technical and historical details on the development,
operation and installation of the Ferranti Sirius at Monash University. We have
also received advice from John Feist, Chris Burton and a large number of staff
and students who had experience with using the Sirius installations at Monash
University - Clayton campus and Caulfield campus, as well as ICIANZ’s
computer. Former employees of Ferranti Ltd in Melbourne have also contributed
their knowledge to this research project. Staff at Monash University Archives
provided access to the University’s early files on computing.

You Can Become a Computer Programmer!

Dik Leatherdale

In the early 1970s, the IT industry was expanding at an astonishing rate. There
was a severe shortage of programmers and other IT staff. That caused salaries to
rise very quickly (Oh happy days!). In London, programming training schools
appeared, like a rash, all over the West End. Some of them were good and some
less good, but they all held out the promise of a lucrative career in IT to the
unsuspecting public.

One such organisation advertised heavily on London Underground trains. They used
a variant of the old IBM aptitude test. Five number series were shown each
followed by a “?”. The strap line was “If you can do three of
these puzzles by the station after next, you can become a computer
programmer.”. Obviously, being a computer programmer was the aspiration of
every right-thinking person. Every few weeks the series were changed. Naturally,
those of us already in the business couldn’t resist the challenge.

Well, the training school wasn’t in the business of putting people off, so
the puzzles weren’t very hard. Or, at least, three of the series
weren’t very hard. Anybody who was half-way competent could solve three of
them by the time the back of the train had left the station. Generally, the
fourth took a little longer and the fifth was the difficult one, but could
indeed, usually be solved by the station after next.

Then, one day, a new puzzle appeared. And the difficult one was more difficult
than usual. Not only could it not be solved by the station after next, the end
of the line was encountered before I had made any headway. In fact, it took me
three whole days.

Now, given the rather superior collective intellect of the Computer Conservation
Society, I suspect that many of you will do better than I did. So let’s
see:

110 , 20 , 12 , 11 , 10 , ?

The first few people to email the correct next number (preferably with an
explanation) to the editor will be acknowledged in the next issue of
Resurrection.

Letters to the Editor

From Harold Hankins

Ron Foulkes’ article on the development of the MetroVick 950 and AEI 1010
computers (Resurrection 43) reminded me of the time I was working in adjacent
laboratories, during the early 1960s, leading a team responsible for the
development and design of the AEI Type 1200 telecontrol and computer display
system.

The development of the type 1200 was a commercial attempt by AEI in 1961 to
break into the emerging remote monitoring, control and display markets of the
public utilities, offering digital systems with greater flexibility than
existing analogue ones. The type 1200 used digital circuits from the AEI 1010
computer to realise all the logic functions for the outstations and a control
centre. They were of hard wired fixed logic design, to generate the necessary
outstation control algorithms and error correcting messages. AEI’s
experience in developing radar displays led to a decision to use a 21”CRT
on which to display outstation information using electronically generated
English characters, numerals and special symbols on a 4 x 4 matrix, together
with basic line diagrams. In 1961, no such systems were commercially available,
although today they are commonplace.

The CRT display system was of the random scan type, allowing the CRT beam to be
positioned at any point on the screen, rather like a pen being positioned on a
piece of paper. Once positioned, X & Y deflection signals derived from the
selected 4 x 4 diode matrix drew the character on the CRT screen. The CRT
display unit required sophisticated analogue circuitry, using ultra linear
deflection transistor amplifiers, magnetic focussing and deflection of the beam,
pin cushion magnets to correct for distortion, dynamic focussing of the CRT beam
to all points of the display area and rapid defocusing of the beam, should the
scanning system fail, to avoid burning a hole in the phosphor. The L4 fluoride
phosphor, developed by Ferranti, was flicker free when refreshed 12 times per
second, giving a pleasant orange on black display when viewed through a neutral
density filter fixed to the face of the CRT.

The AEI 1200 Display

The display file holding the required alpha numeric character codes was based on
the AEI 1010 magnetic core store, together with the same read-write circuitry,
for the required 4096 words of six bit length, instead of the computer’s
44 bit length. The character 4 x 4 matrix was a committed diode array mounted on
the same 10 ″x 8″ PCBs as used in the 1010 computer. The magnetic
core store was read continuously 12 times a second and a one MHz clock drove the
character generator at 50,000 characters per second for a flicker free display.

The computer display prototype was demonstrated in 1962 to Dick Grimsdale, who
had left Manchester University to join AEI (Automation), and to Max Jervis
(CEGB). The CEGB had contracted AEI (Automation) to produce an Alarm Analysis
System using the AEI 1010 Computer at the Oldbury Nuclear Power Station then
being constructed by AEI. A type 1200 computer display system, interfaced to the
1010, using the same logic PCBs where necessary and housed in type 1010
cabinets, was then ordered by the CEGB, together with a number of 21″ CRT
displays, to help reduce the size and number of control and indicator panels in
the Control Room. The overall system became operational in 1964, being one of
the first, if not the first, commercial application of a computer display
system. The prototype won “Best Industrial Exhibit” at the IEA
Exhibition at Earls Court in the same year.

A second system was ordered for use in another Nuclear Power station, interfaced
to a GEPAC 4000 computer which had been acquired by AEI (Automation) under
licence from GE of America, to replace the AEI 1010. If I recall correctly,
another was used in a steel works application using a GEPAC 4000.

Another computer display system known as the type 1400, interfaced to Ferranti
type 1600 computers, was ordered for use in an Admiralty simulator project. The
type 1400 was a modified type 1200 computer display, with a character generator
capable of producing 250,000 characters per second for a multiplicity of
24″ circular, horizontally-mounted CRTs.

The AEI type 1200 telecontrol system was never put into production. The Midlands
Electricity Board acquired the prototype and installed it at the Hanley Control
Centre where the late Horace Heath (MEB) and Mike Jennions (AEI) carried out
some interesting pioneering experiments on digital telemetry and control of
electrical distribution networks.

The AEI 1010 - an Additional Note

Ron Foulkes

Due to an editing error, a paragraph was inadvertently omitted from Ron
Foulkes’ article on the AEI 1010 in Resurrection 43. Readers will recall
that there is a discussion of the 1010’s ability to timeshare. Although
Resurrection has considered the introduction of timesharing in some detail, the
means by which it was achieved have received less attention. Ron went on to
describe how it was done on the 1010 as follows -

The process was controlled by a continuously running housekeeping routine. It
could instruct the central processor to stop working on one application and
start or restart working on another. It was a piece of software that had sole
use of 99 blocks on the magnetic drum and 11 blocks in the working store. The
housekeeping routine allowed for up to four parallel programs which, between
them, could have up to nine parallel branches. This allowed the programmer to
use parallel working within one application program.

Contact details

Readers wishing to contact the Editor may do so by email to
,
or by post to 124 Stanley Road, Teddington, TW11 8TX.
Queries about all other CCS matters should be addressed to the Secretary, Kevin Murrell, at
,
or by post to 25 Comet Close, Ash Vale, Aldershot, Hants GU12 5SG.

Forthcoming Events

Every Tuesday at 12:00 and 14:00 Demonstrations of the replica Small-Scale
Experimental Machine at Manchester Museum of Science and Industry.

Every day Guided tours and exhibitions at Bletchley Park, price £10.00,
or £8.00 for concessions (children under 12, free). Exhibition of wartime
code-breaking equipment and procedures, including the replica Bombe and replica
Colossus, plus tours of the wartime buildings. Go to
www.bletchleypark.org.uk to
check details of times and special events.

Lecture Programme

13 November 2008 London seminar “Iconic machines: Exhibiting a History of
Computing”. Speaker Doron Swade.

12 March 2009 London seminar “The Archaeology of Very Early Algorithms
1948-58 : Strachey’s Love Letter Generator”. Speaker David Link.

23 April 2009 London seminar “JANET - the First 25 Years”.

14 May 2009 London seminar “BBC Domesday Book Project”.

Details are subject to change. Members wishing to attend any meeting are advised
to check the events page on the Society Web site at
www.computerconservationsociety.org
for final details which will be published in
advance of each event. Details will also be published on the BCS Web site (in
the BCS events calendar) and in the Events Diary columns of Computing and
Computer Weekly. London meetings take place in the Director’s Suite of the
Science Museum, starting at 14:30. North West Group meetings take place in the
Conference Room at the Manchester Museum of Science and Industry, usually
starting at 17:30; tea is served from 17:00.

Queries about London meetings should be addressed to Roger Johnson at
, or by post to Roger at Birkbeck College, Malet Street,
London WC1E 7HX. Queries about Manchester meetings should go to William Gunn at
.

Point of Contact

Readers who have general queries to put to the Society should address
them to the Secretary: contact details are given elsewhere.
Members who move house should notify Kevin Murrell of their new
address to ensure that they continue to receive copies of Resurrection.
Those who are also members of the BCS should note that the CCS membership is
different from the BCS list and is therefore maintained separately.

Aims and objectives

The Computer Conservation Society (CCS) is a co-operative venture
between the British Computer Society, the Science Museum of London and the
Museum of Science and Industry in Manchester.

The CCS was constituted in September 1989 as a Specialist Group of
the British Computer Society (BCS). It thus is covered by the Royal
Charter and charitable status of the BCS.

The aims of the CCS are to

Promote the conservation of historic computers and to identify existing
computers which may need to be archived in the future

Develop awareness of the importance of historic computers

Encourage research on historic computers and their impact on society

Membership is open to anyone interested in computer conservation and
the history of computing.

The CCS is funded and supported by voluntary subscriptions from members,
a grant from the BCS, fees from corporate membership, donations, and by
the free use of Science Museum facilities. Some charges may be made for
publications and attendance at seminars and conferences.

There are a number of active Working Parties on specific computer
restorations and early computer technologies and software. Younger people
are especially encouraged to take part in order to achieve skills transfer.

Resurrection is the bulletin of the
Computer Conservation Society. Copies of the current issue are available
from the Secretary for £5.00 each.